Expansible drill



G. D. HAYDEN EXPANSIBLE DRILL Filed Dec. 1950 FI G.4.

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GEORGE D. HAYDEN ATTORNEYS Patented Nov. 24, 1953 UNITED STATESEXPANSIBLE DRILL George D. Hayden, Detroit, Mich., assignor to HaydenTwist Drill Company, Detroit, Mich., a corporation of MichiganApplication December ll, 1950, Serial No. 200,281

1 Claim.

The present invention relates to expansible or adjustable drills and hasamong its objects the provision of a drill capable of drilling intosolid metal and of greatly enlarging such a hole by a simple adjustment.

Another object of the invention is a drill of the type indicated whichshall be simple in construction and operation and which shall consist ofonly a few parts.

Still other objects and advantages will be apparent to those skilled inthe art upon reference to the following description and the accompanyingdrawings in which Fig. 1 is a side view in elevation of the drill asadjusted for an increased size of hole.

Fig. 2 shows a similar view of the drill point as adjusted for drillingin a solid.

Fig. 3 is a section on line 3-3 of Fig. 1.

Fig. 4 is a section on line 4-4 of Fig. 1.

Fig. 5 is a top plan of the adjusting ring.

Fig. 6 is a bottom plan of one of the bits or blades.

Fig. 7 is a side elevation of the same.

Fig. 8 is a sectional view showing a modified structure.

As indicated in the drawing, the drill consists of a body I providedwith a shank IOA suitable for insertion into a suitable chuck and asomewhat enlarged cylindrical portion at the opposite end terminating inblade holding portion II. This blade holding portion is provided with apair of jaws IIC produced by cutting a deep diametrical slot IIA, theside walls of which are accurately parallel and. each provided with ashallow rectangular groove IIB extending across the axis of the body.Further, a suitable passage is drilled diametrically through the jawsand countersunk as at I I0 to receive a suitable screw IID, this beingthreaded into the wall opposite the countersink.

In the slot I IA are mounted a pair of blades or drill points I2 whichare identical but arranged as right and left. These blades are of the.form shown in Fig. '7, being each provided with a cutting point I 2A,and a groove IZB of the same size as groove HE and located so as toregister with the latter when the blade is in place in the jaws I IC.The blades l2 are also provided on the bottom edges, that is, the edgeopposite the point IZA, with a series of spirally curved teeth I20, andwith a slotted opening I2D.

Carried by the body I0 is a ring I3 of substantial thickness havingformed on one of its edges a double scroll or spiral groove I3A adaptedto mesh with the teeth I2C on the blades I2. Also carried by the body I0is a second ring I4, this acting as a backing ring and bearing for ringI3.

A third ring I is also carried by the body and threaded thereon asindicated at ISA and provided with a set screw I 5B.

As indicated in Figs. 1 to 4, the two blades are mounted in the jaws IICbeing placed right 2 and left with plates I6 in the grooves HE and [2Band serving as guides. The plates I6 are provided with openings fittingthe screws IID.

The ring I3 meshing with teeth IZ-C serves to fix and adjust theposition of the blades and the ring I5 serves to maintain the parts inadjusted position.

When the blades I2 are in the position shown in Fig. 2, the drill may beused to drill in solid metal. The hole produced may then be enlarged upto the widest adjustment of the blades I2 by loosing screw IID and ringl5, turning ring I3 to move the blades, and tightening again the 1parts.

In Fig. 8 the jaws II are shown as provided with suitable slides Dtaking the place of the separate members I6.

In the above description, the blades are described as right and left.This refers only to the operation of assembling. Further, in order toprovide for proper operation at the limits of the adjustment, the drillpoint or blades must be so formed that the point l2A is in line with thecenter of the inner end of the slot and that distance B be slightly lessthan the distance C.

By making the ring I3 with a double scroll as mentioned, the blades [2may be made identical and interchangeable. It is obvious that severalsets of blades may be used in a single body to increase the range ofsizes of holes, and this is contemplated.

I claim:

An adjustable drill capable of drilling in solid material said drillcomprising a body having at one end a shank and at its other end a pairof jaws, a pair of blades in said jaws, each having 5a drilling pointand inclined cutting edge, said blades arranged in said jaws inoverlapping parallel planes and being identical but arranged as rightand left, means for adjusting the positions of said bladessimultaneously and ,equally, whereby to bring said points together toReferences Cited in the file of this patent UNITED STATES PATENTS NumberName Date 457,536 Jennings -l Aug. 11, 1891 613,660 iBrunner Nov. 8,1898 1,446,662 Samuel Feb. 27, 1923 FOREIGN PATENTS Number Country Date551,148 Great Britain Feb. 9, 1943

